Question

Secondary body cavity with segmented mesodermal lining is called as
A) Hemocoel
B) Neurocoel
C) True coelom
D) Pseudo coelom

Answer 1

Coelom is the body cavity that is lined with mesoderm. Secondary body cavity has mesodermal lining in segmented form and is called true coelom. The animals which possess true coelom are called coelomates. For example, annelids, molluscs, arthropods.

Complete answer:
The body cavity includes all the cavities president in the body. There are different types of body cavities.
Acoelomate:-The coelom is not present, E.g, Platyhelminthes. Acoelomate are of two types

Diploblastic acoelomate
Triploblastic acoelomate
Pseudocoelomate:-The body cavity is not properly lined by mesoderm externally and internally. Mesoderm is present in the pouch or small patches. E.g., Aschelminthes.
Eucoelomate:-The body cavity is lined by a complete layer of mesoderm externally and complete layer of mesoderm internally. E.g., Annelida to Chordata.
The secondary body cavity, which is lined by mesoderm is called a true coelom. A true coelom is covered by a mesoderm that gives rise to muscles that surround the gut, the body wall.A coelom is a space between the gut tube (lined with endoderm) and the body wall (with its outer covering of ectoderm). Coelenteron is the central gastric cavity of a coelenterate. Pseudocoel is non-aligned with a proper mesodermal membrane. Blastocoel is the fluid-filled region of a blastula.

Thus,option ‘C’ True coelom is the correct answer.

Notes: In humans, there are four modified coeloms, two for lungs (pleural cavity), one for the heart (pericardial cavity), one for other abdominal organs (peritoneal cavity).